What role does temperature play in the operation of the APU?

Temperature significantly influences the performance and operational efficiency of the APU. As environmental temperatures change, the APU's fuel efficiency can be directly impacted. In higher temperatures, for example, the fuel may vaporize more readily, which can lead to variations in the combustion process, ultimately affecting how effectively the engine operates. Conversely, in lower temperatures, the viscosity of fuels changes, leading to potential performance issues that might not be as pronounced in moderate conditions.

Additionally, temperature can influence the overall operational time of the APU. Cold starts typically require more energy and fuel, which may reduce the overall efficiency during initial operation. Therefore, the management of temperature and understanding its effects are crucial for optimizing both fuel usage and maintenance schedules for the APU. This aspect is vital for ensuring that the APU operates within its designed performance parameters, thereby allowing for the effective support of the aircraft’s systems during ground operations.